U.S. Pat. No. 3,274,160 discloses the preparation of a hard, elastic NCO terminated polyurethane casting entailing reacting a polyisocyanate with a mixture containing a polyhydric alcohol and an organic compound having a plurality of alcoholic hydroxyl groups. In U.S. Pat. No. 3,591,561 there is disclosed the preparation of a polyurethane elastomer prepared from a lactone polyester polyol and a low molecular weight diol. The mixture of polyol and diol may then be reacted with organic diisocyanate and crosslinked with an aliphatic or an aromatic diamine or polyol such as glycerol. A polyurethane elastomer based on a polyether polyol, an extender--including glycerine--an isocyanate terminated prepolymer and an organometallic catalyst is disclosed in U.S. Pat. No. 3,725,355. A polyurethane composition from an amine initiated polyol, organic polyisocyanate and a modifier, including a glycerine initiated polyoxyalkylene compound is disclosed in U.S. Pat. No. 4,028,301. In U.S. Pat. No. 4,182,898, there are disclosed polyester polyether polyol prepolymers for use in the preparation of polyurethane. Before reacting with a diisocyanate, there are incorporated in the polyol mixture low molecular weight diols or polyols such as glycerine.
A method for making bonds which are based on polyisocyanates and compounds containing isocyanate reactive hydrogen was disclosed in U.S. Pat. No. 4,193,832. Tertiary amines are said to be suitable catalysts in the reaction. A process for the manufacture of a polyurethane adhesive is disclosed in U.S. Pat. No. 4,156,064. Accordingly, a polyaddition reaction is carried out by using excess diisocyanate in a reaction with polyols and optional chain extenders which include diamines. U.S. Pat. Nos. 3,979,364, 4,336,298, and 4,444,976 and European Pat. No. 63,534 all relate to the addition of amines in making non-sagging adhesives.
U.S. Pat. No. 4,487,909 discloses an adhesive system prepared from a polymeric polyol precursor such as a polyether polyol. A glycerine branching agent is disclosed. RIM polyurethane prepared from a high molecular weight polyol, a chain extender, a polyisocyanate and an aminated polyoxyalkylene material has been disclosed in U.S. Pat. No. 4,530,941. The preparation of the polyol is said to be in the presence of an initiator such as glycerine or an aliphatic diamine. In U.S. Pat. No. 4,554,340, there is disclosed a polyol mixture for use in the preparation of polyurethane. The polyol mixture comprises a high molecular weight polyalkylene oxide, low molecular weight diol and optionally isocyanate-reactive compounds including glycerine and diamines. In accordance with the disclosure, the polyol mixture is mixed with polyisocyanates and optionally other polyols. In U.S. Pat. No. 4,568,717, there are disclosed polymer polyols which are made by reacting a terephthalic polyester polyol with an organic polyisocyanate. The polyester polyol may be prepared by reacting polyethylene terephthalate with oxyalkylene glycol. The functionality of the polyol may be changed by including glycerine or diethanolamine.
In U.S. Pat. No. 3,714,127 there is disclosed the addition of a diamine to a two component polyurethane based adhesive for the purpose of increasing the viscosity of the adhesive to eliminate run-off or dripping. The adhesive is based on a polyisocyanate terminated prepolymer.